Detective Sing was sitting at his desk when he was approached by a young lady.

"I've come to you for advice, Detective Sing," she said. "I met this guy, Dr. Howard, a few months ago. He's an archaeological expert, specialising in sun rituals in ancient times. A few days ago he approached me and said that he had found a beautiful vase which had pictures on it celebrating the Summer Equinox. He said that it's a rare find, but that if I give him $2000, he'll give me a half share in any proceeds he gets when he sells the vase. I was wondering whether you could find out some more about him for me, to make sure I'm not going to be handing over money to a fraud."

"Well," said Detective Sing. "The vase may well be a genuine artifact, but I'd be careful of this guy 'Howard' - he's a fraud."

What made Detective Sing so sure?